Robotically manipulable sample handling tool

ABSTRACT

A sample handling tool, such as a colony picking head or robotic pipetting tool, includes sample handling needles, e.g., capillaries, arranged on the tool. Actuators are associated with each capillary to control flow for the capillary, e.g., to move the capillary and/or draw fluid into/expel fluid from the capillary. The actuators are arranged so that capillaries may be individually controlled by a controller that is capable of outputting a number of control signals that is less than the total number of capillaries. The actuators may be valves that receive two signals from a controller, a first signal that opens or closes the valve, and a second signal that allows fluid to flow in the valve.

This application is a continuation-in-part of International Application No. PCT/US03/09470, filed Mar. 28, 2003, which is an international application of, and claims the benefit of/priority to, U.S. application Ser. No. 10/113,865, filed Apr. 1, 2002, now U.S. Pat. No. 6,637,476. Application Ser. Nos. PCT/US03/09470 and 10/113,865 are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to robotically manipulable sample handling tools, such as robotic pipetting devices.

2. Related Art

Robotically manipulated tools having a plurality of picking needles are widely used, for example, in proteomic and genomic research. These devices are used to move material samples both to and from a variety of different work areas, such as microtiter trays, gels having separated DNA fragments, and other material holding devices. Some such tools may have a plurality of needles arranged in an array that corresponds to wells in a microtiter tray, such as the commonly-known 96-well or 384-well plate. The array of needles arranged to correspond with all of the wells in a microtiter tray may allow material to be simultaneously deposited in, and removed from, wells in the microtiter tray, thus increasing the speed at which a plurality of samples in a microtiter tray may be processed.

SUMMARY OF THE INVENTION

In one illustrative embodiment in accordance with the invention, a robotically manipulable material handling tool includes a body and a plurality of needles mounted to the tool body. Each of the plurality of needles is constructed and arranged to remove material from a work area and/or deposit material on a work area. The tool also includes a plurality of actuators that each correspond to one of the plurality of needles. The actuators are constructed and arranged to actuate a corresponding needle and are grouped into a first number of control groups and a second number of drive groups, with each control group and drive group having only one actuator in common. A plurality of control switches may each be associated with a corresponding control group of actuators and adapted to provide a control signal to actuators in the corresponding control group. A plurality of drive switches may be associated with a corresponding drive group and adapted to provided a drive signal to the actuators in the corresponding drive group. The plurality of control switches and drive switches are constructed and arranged to provide control signals and drive signals, respectively, to individually actuate each of the plurality of needles.

In another illustrative embodiment, a sample handling tool includes a body and a first number of needles mounted to the tool body. As used herein, a “needle” refers to any suitable arrangement for handling a sample, such as a capillary tube or element, a pipette channel, a removable pipette tip, a coring device, etc. Each of the needles, e.g., capillaries, is constructed and arranged to remove material from a work area and/or deposit material on a work area. A controller is constructed and arranged to control the capillaries so as to simultaneously actuate a plurality of the capillaries, and is adapted to control the capillaries so as to individually actuate each capillary independent of other capillaries. For example, the controller may be adapted to individually control flow for each capillary.

In another illustrative embodiment, a sample handling tool includes a body and a first number of needles mounted to the body. Each of the needles may be constructed and arranged to remove material from a work area and/or deposit material on a work area. The tool may also includes a first number of actuators with each actuator associated with a corresponding needle and constructed and arranged to actuate the corresponding needle. A controller may be constructed and arranged to control each of the actuators by providing a maximum of a second number of signals to the actuators where the second number is less than the first number. The controller may be adapted to control the actuators and individually actuate needles and/or simultaneously actuate a plurality of needles. As used herein, one “signal” used by the controller to control an actuator and/or actuate a needle refers to a signal having one or more possible states. Thus, the controller is said to be capable of providing one “signal” to an actuator although the one “signal” may set the actuator in different states, e.g., on/off, enable/disable, etc, and the one “signal” may have two different forms to cause the different actuator states, e.g., high or low. For example, a controller may be adapted to provide one “signal” to an actuator to put the actuator in an enable or disable state. The one “signal” may have one state, e.g., a high pressure, to place the actuator in an enable state, and a second state, e.g., low pressure, to place the actuator in a disable state.

In another illustrative embodiment, a sample handling tool includes a body and a plurality of needles mounted to the tool body in M columns and N rows. Each of the needles may be constructed and arranged to remove material from a work area and/or deposit material on a work area. A plurality of valves may each be associated with a corresponding needle and control flow for the needle. A plurality of switches may provide signals to the valves to actuate the needles, either individually or in selected groups. The total number of signals used by the plurality of switches may be no more than M+N.

These and other aspects of the invention will be apparent and/or obvious from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrative embodiments in accordance with the invention are described below with reference to the following drawings, in which like numerals reference like elements, and wherein:

FIG. 1 is a schematic diagram of a sample handling tool in accordance with the invention;

FIG. 2 is a schematic, perspective view of a tool in accordance with the invention;

FIG. 3 is a plan view of the tool shown in FIG. 2 and illustrates how individual needle actuators may be addressed; and

FIG. 4 is a cross-sectional view along the line 4-4 in FIG. 3.

DETAILED DESCRIPTION

Various aspects of the invention are described below with reference to illustrative embodiments. However, it should be understood that the invention is not limited to those embodiments described below, but instead may be used in any suitable system or arrangement.

In one aspect of the invention, needles in a tool may be individually actuated or otherwise controlled by a controller that is capable of outputting a maximum number of signals that is less than the total number of needles on the tool. For example, if the tool has an M×N array of needles, the controller may be arranged to output a maximum of number of signals that is less than M×N, yet still be capable of individually actuating selected needles. Such actuation may include moving a needle relative to the tool, such as extending the needle away from the tool apart from other needles on the body, controlling flow in the needle, such as allowing fluid to flow into or expelling fluid out from the needle, or otherwise causing the needle to perform one or more material handling functions. In addition, the controller may simultaneously actuate all needles in the array, or simultaneously actuate selected groups of needles, such as all or selected needles in a particular row or column of needles. This arrangement may allow individual control of needles without requiring a controller to output an individual control signal for each needle.

In one aspect of the invention, actuators in a material handling tool may be grouped into control groups and drive groups, where each control group has one actuator in common with each drive group. Actuators in a control group may be linked so that a common control signal may be simultaneously provided to all actuators in the control group, e.g., to cause the actuators to be in an enable state ready to actuate a corresponding needle. Actuators may also be linked so that a common drive signal may be simultaneously provided to all actuators in a drive group, where the drive signal causes actuation of a needle when received by an actuator in an enable state. Since control groups and drive groups include one actuator in common, a particular needle may be actuated by providing a control signal to the needle's control group and providing a drive signal to the needle's drive group. That is, a needle may be actuated only when its corresponding actuator receives both an appropriate control signal and an appropriate drive signal. Accordingly, individual actuation of needles can be effected by a controller without requiring the controller to output control signals for each needle. Instead, the controller may be arranged to output a maximum number of control signals that is less than the number of needles, e.g., equal to the total number of control and drive groups. Such an arrangement also allows for simultaneous actuation of all needles in the tool, or selected groups of needles.

FIG. 1 is a schematic diagram of a robot 1 manipulating a sample handling tool 10 in accordance with the invention. The robot 1 may move the sample handling tool 10 and allow needles 4 on the tool 10 to pick up and/or deposit material on one or more work areas, such as microtiter trays, gels containing separated DNA fragments or other biologic materials, a bath containing a wash solution, etc. For example, the robot 1 may move the tool 10 so that one or more needles 4 are appropriately positioned with respect to a microtiter tray and then actuate one or more needles 4 to remove material from, or deposit material in, wells in the microtiter tray. Those of skill in the art will understand that the needles may be actuated to perform other material handling operations, such as colony or plaque picking at the direction of a machine vision system. The purposes and methods for such material handling are well known to those in the art and not described in detail herein.

In the illustrative embodiments described below, the needles 4 may be capillary elements, e.g., capillary tubes or other structures, suitable for picking up a liquid that enters the element by capillary action. The capillaries may be arranged to fill completely, or fill to a specific level. For example, capillaries may have a flow restrictor positioned in the capillary channel that prevents filling of the channel past the restrictor. Alternately, the channel may have an affinity gradient, e.g., a lower part of the capillary channel may have a relatively high affinity for the liquid while an upper part of the capillary may have a lower affinity, and thus capillary filling of the channel may stop at the high affinity/low affinity boundary. Filling of the capillaries may aid in controlling the volume of liquid picked up and/or dispensed by the capillary. Sample volumes picked up/dispensed by the capillaries may controlled to be in the nanoliter range, or higher or lower as desired. Volume control may alternately be controlled by a metering piston or other arrangement that closely controls the flow through capillaries. Thus, capillaries may be controlled to pick up/dispense a desired volume of fluid by controlling a flow of fluid into/out of a line in communication with the capillaries.

Although the robot 1 is shown in FIG. 1 as having a base and an articulated arm, the robot 1 may be of any suitable type or construction and may be capable of moving the tool 10 in any suitable number of degrees of freedom. For example, the robot may be a gantry-type robot capable of moving the tool 10 in three degrees of freedom. Of course, other suitable robotic configurations capable of moving the tool 10 in one or more degrees of freedom may be used. The tool 10 and robot 1 may include a coupling to allow the robot 1 to exchange the tool 10 for other tools, thereby allowing the robot 1 to perform automated operations with different tools. The robot 1 or system controller may include a vision system or other suitable device to control positioning of needles 4 with respect to target areas, as is well known. In addition, a connection between the tool 10 and the robot 1 may provide physical support to the tool 10 as well as provide electrical power, control signals, a fluid supply or other fluid signal, etc. As used herein, “fluid” refers to gases and/or liquids and/or liquids that include or contain solid particles. It should also be understood that the tool 10 need not be manipulated by a robot 1, but may be fixed in place or moved on one or more directions by a non-robotic system, such as in some dedicated liquid handling systems.

In the illustrative embodiment of FIG. 1, the tool 10 includes a controller 2 that outputs signals to actuators 3 that cause corresponding needles 4 (in this illustrative embodiment, capillaries) to be actuated. As discussed above, actuation of a needle 4 may cause the needle 4 to move relative to the tool 10, such as extend away from the tool to pick or place material on a work area, control flow in the needle, such as drawing fluid into or expelling fluid out from the needle, or otherwise cause the needle to perform one or more material handling functions. In this illustrative embodiment, the controller 2, actuators 3 and needles 4 are all mounted to a body 5 of the tool 10, but the controller 2 and/or actuators may be arranged off of the tool 10. Although in this illustrative embodiment the body 5 has a box-like shape, the body 5 may be arranged in any suitable way. Further, the needles 4 in this illustrative embodiment are arranged in a 3×4 array and extend from a bottom of the body 5, but any suitable number of needles 4 may be arranged in any suitable way on the body 5, e.g., to accommodate particular well patterns in a microtiter tray. The needles 4 may be removably mounted to the tool (e.g., to allow replacement of one or more capillaries), and/or permanently fixed to the tool body.

The controller 2, which may in some embodiments be provided off of the tool 10, may provide any suitable signal or combination of signals to the actuators 3 to actuate the needles 4. For example, the controller 2 may provide electrical signals, magnetic signals, optical signals, fluid signals (e.g., changes in fluid pressure and/or flow), or combinations of such signals, such as providing both an electrical signal and a fluid signal to the actuators 3. Typically, signals provided by the controller 2 will depend upon the type of actuators 3. For example, the actuators 3 may be pneumatically-controlled fluid valves that open, close or otherwise change state based on a fluid signal. Of course, the actuators may include electrically-controlled fluid valves, solenoids, relays, or other suitable devices to actuate a corresponding needle. For example, the tool 10 may include one actuator for each needle, where each actuator includes a valve and associated pneumatic ram such that when the valve is open and air pressure is supplied through the open valve, the pneumatic ram may extend, and thereby extend a corresponding needle 4 from the body 5. Thus, the actuators may be responsive to two signals received from the controller 2 to actuate the needles 4. Having the actuators 3 respond to two signals from the controller 2 may allow for matrix-type addressing of the actuators 3, as discussed in more detail below.

The controller 2 may operate autonomously to actuate the needles 4 or operate at the direction of a higher level controller that is part of a material handling system. For example, the controller 2 may receive a high-level signal to activate a particular needle or group of needles at a particular time and/or position of the tool 10, and generate and output appropriate signals to cause the desired actuation. The controller 2 may receive the signals in any suitable way, such as by wired and/or wireless link, and in any suitable format and/or communications protocol. The controller 2 and/or higher level controller may include any suitable general purpose data processing system, which can be, or include, a suitably programmed general purpose computer, or network of general purpose computers, and other associated devices, including communication devices, and/or other circuitry or components necessary to perform the desired input/output or other functions. The controllers can also be implemented at least in part as single special purpose integrated circuits (e.g., ASICs), or an array of ASICs, each having a main or central processor section for overall, system-level control and separate sections dedicated to performing various different specific computations, functions and other processes under the control of the central processor section. The controllers can also be implemented using a plurality of separate dedicated programmable integrated or other electronic circuits or devices, e.g., hardwired electronic or logic circuits, such as discrete element circuits or programmable logic devices. The controllers may also include other devices, such as an information display device, user input devices, such as a keyboard, user pointing device, touch screen or other user interface, data storage devices, communication devices or other electronic circuitry or components.

FIG. 2 shows a perspective view of a tool 10 in accordance with the invention. In this illustrative embodiment, the tool 10 includes a 3×4 array of actuators 3 that are each associated with a corresponding needle 4. Thus, when an actuator 3 receives appropriate signals, the corresponding needle 4 is actuated, e.g., fluid flow in the needle is controlled and/or the needle 4 is moved relative to the body 5. In this illustrative embodiment, the controller 2 includes four control switches 21 that are associated with actuators 3 in rows across the tool 10, and drive switches 22 that are associated with actuators 3 in columns on the tool 10. Control signals may be provided to the control switches 21 and drive switches 22 by a portion of the controller 2 (e.g., a data processor and associated memory) on the tool 10, or by another source off of the tool 10. Based on these control signals, the control switches 21 and drive switches 22 may provide suitable signals to the actuators 3 to actuate a particular needle or needles. The switches 21 and 22 may be any suitable device capable of responding to a control signal and providing a signal to corresponding actuators 3. For example, the switches 21 and 22 may include electrically-controlled or pneumatically-controlled valves capable of switching an associated control or drive line 23 or 24 between one or more fluid supply lines, e.g., sources of relatively high, low and/or ambient pressure, or sources of fluid flow. Pressure or other fluid flow sources may be provided to the switches 21 and 22 by lines (not shown) that lead to a pump, metering piston or other devices off of the tool body 10.

It should be understood that although the actuators 3 in this illustrative embodiment are arranged in columns and rows, the actuators 3 may be logically grouped in any suitable way and in any suitable pattern. Further, the tool 10 is not limited to a 3×4 array, but instead may have any suitable number of actuators and/or needles arranged in any suitable pattern, such as a pattern that allows the needles 4 to interact with standard 96-well, 384-well or other size/configuration microtiter trays or other material sample holders. Thus, the 3×4 array in this illustrative embodiment is used for simplicity and ease of reference, but should in no way be interpreted as limiting aspects of the invention in any way.

FIG. 3 shows a schematic top view of the tool 10 shown in FIG. 2. Rows of actuators 3 are labeled A-D, and one control switch 21 may correspond to each row A-D. Similarly, columns of the actuators 3 are numbered 1-3 and one drive switch 22 may correspond to each column 1-3. In this illustrative embodiment, each control switch 21 provides a control signal (e.g., a signal having two or more states) approximately simultaneously to all actuators 3 in the corresponding row via a control line 23. Thus, control groups of actuators 3 in this embodiment are arranged in rows. The control signal provided to a control group may cause the actuators 3 in the group to change state between an enable state and a disable state. In the disable state, an actuator 3 may be unable to actuate a corresponding needle 4. In the enable state, the actuator 3 may be free to actuate the corresponding needle 4 upon receipt of an appropriate drive signal. Each of the drive switches 22 may approximately simultaneously provide a drive signal to all actuators 3 in a corresponding column along a drive line 24. Thus, drive groups in this embodiment are arranged in columns. The drive signal may cause actuators in an enable state to actuate a corresponding needle 4. However, in this embodiment, an actuator in a disable state may not actuate a corresponding needle even if a drive signal that would otherwise cause actuation is received.

Accordingly, individual actuators may be caused to actuate a corresponding needle 4, i.e., individual actuators 3 may be addressed, by providing a control signal (e.g., causing an enable or disable state of the actuators) along the actuator's corresponding control line 23 and a drive signal (e.g., causing a flow or no flow condition) along the actuator's corresponding drive line 24. For example, the actuator 3 in the top right corner of the tool 10 as shown in FIG. 3 may be addressed by providing a control signal from the control switch 21 for row A and providing a drive signal from the drive switch 22 for column 3. Other actuators in the row A and in column 3 will not actuate a corresponding needle 4 unless an appropriate control signal and drive signal are received along appropriate lines. Thus, when the actuator 3 in the top right corner of the tool 10 (i.e., position A-3) is actuated, actuators in the row A and in columns 1 and 2 will not be actuated unless drive signals are provided by the drive switches 22 for columns 1 and 2. As a result, individual needles 4 may be actuated by providing appropriate signals to groups, e.g., rows and/or columns, of actuators in the tool 10.

It should also be appreciated that selected groups of actuators 3 may be addressed by providing appropriate signals along the rows A-D and columns 1-3. For example, all needles on the tool 10, or selected needles, in a particular row or column may be approximately simultaneously actuated, e.g., all of the actuators 3 in row A may be actuated by providing an appropriate control signal from the control switch 21 for row A and appropriate drive signals from the drive switches 22 for columns 1-3. It will be appreciated that other selected groups of needles may be approximately simultaneously actuated by providing signals on appropriate control and drive lines 23 and 24.

FIG. 4 shows a cross-sectional view of the tool 10 along the line 4-4 in FIG. 3. As discussed above, the actuators 3 may take any suitable form, but in this illustrative embodiment, include one or more valves 31. The various control lines 23, drive lines 24, needle channels 33, valves 31 and other features may be formed in upper and lower blocks 11 and 12 of the tool body 10. The blocks 11 and 12 may be made of any suitable material(s), such as plastic, and the channels, lines, chambers and other features may be formed in any suitable way using any suitable process. For example, each block may be made of multiple layers of plastic material that have grooves, channels or are otherwise formed to create the desired lines, channels, etc. in the tool body 10. These layers may be joined together, e.g., by heating the layers and pressing them together, to form a unitary block.

In one illustrative embodiment, the valves 31 may be poppet-type fluid valves that are located within, partially within or outside the tool body 5. Such a valve may be opened to allow fluid to flow in a corresponding needle 4, e.g., to allow the capillary to pick up a liquid sample by capillary action. Conversely, if a poppet valve actuator for a capillary is closed, fluid flow in the capillary can be inhibited, and the capillary will not fill with fluid even if the free end of the capillary is inserted into a body of suitable fluid. For example, the valve may have a moveable member that can be put in a first position to prevent flow between a drive line 24 and a needle channel 33 (as shown in FIG. 4), and moved to a second position to allow flow between the drive line 24 and the needle channel 33. The poppet valve actuator can also be used to supply fluid under pressure to a corresponding capillary, e.g., to use air to expel fluid in the capillary and/or to supply a liquid to the capillary that is dispensed from the capillary.

The rows of valves 31 may be connected to a common control line 23, and columns of valves 31 may be connected to a common drive line 24. Signals provided on the control lines 23 in this embodiment may serve to switch the valves 31 between an open (or enable) state and closed (or disable) state. When a valve is in an enable state, a drive signal provided along the valve's drive line 24 may be provided through the valve 31 to an associated needle channel 33. Therefore, a control signal may be provided to valves 31 in a row to switch the valves to an enable state, and a drive signal supplied to a drive line 24 for the valves 31 in an enable state may cause actuation of needles corresponding to the enabled valves 31. For example, when a valve is in an enable state, fluid may flow through the valve to allow a fluid to flow into a corresponding capillary, or expel fluids out of the capillary. Alternately, the drive signal, such as a pressurized fluid flow through the valve 31, may cause a pneumatic ram 32 or other device to move an associated needle 4, e.g., extend the needle away from the tool 10 to pick material from a work area.

The control and drive signals may also cause the valves 31 to perform other actuation operations with respect to the needles, such as pumping fluid through a corresponding needle channel 33 and/or drawing or expelling a metered amount of fluid into or out of a corresponding needle 4. Pumping and metering operations may be performed by, for example, placing the valve 31 in a closed state, closing a drive line 24 for the valve 31 at a drive switch 22, and then placing the valve 31 in an open state, thereby causing fluid to be drawn into the needle 4. Movement of the valve parts may be closely controlled to perform accurate fluid metering through the valve's needle, e.g., by controlling the amount of fluid drawn from the valve by the control line 23. Such control can be performed by a metering piston coupled to the control line 23 or drive line 24, by accurately timing the opening and closing of a valve in the control switch 21 while supplying a constant fluid flow through the valve 31, or other means as will be appreciated by those of skill in the art.

It should be appreciated that although the control and drive switches in this illustrative embodiment control fluid flow to corresponding rows and columns of valves, the switches may provide other signal types to the actuators, such as electrical, optical, magnetic and other signal types. Similarly, the actuators and/or valves 31 in this embodiment may include or be replaced with any other suitable element(s), such as electrical or optical relays, transistors, optical valves, etc., and the actuators 3 may include other drive elements, such as hydraulic rams, solenoid actuators, motors, and so on. Therefore, any suitable arrangement of elements may be used as actuators to receive control and drive signals and actuate a corresponding needle.

While the invention has been described with reference to various illustrative embodiments, the invention is not limited to the embodiments described. Thus, it is evident that many alternatives, modifications, and variations of the embodiments described will be apparent to those skilled in the art. Accordingly, embodiments of the invention as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the invention. 

1. A sample handling tool, comprising: a body; a first number of capillaries mounted to the body, each of the capillaries constructed and arranged to remove material from a work area and deposit material on a work area; a first number of valves, each valve associated with a corresponding capillary and controlling flow for the capillary; and a valve controller constructed and arranged to control each of the valves by providing a maximum of a second number of signals to the valves, the second number being less than the first number; wherein the valve controller is adapted to control the valves to individually control flow for each capillary, and wherein the plurality of capillaries and corresponding valves are arranged in an M×N array with control groups of valves arranged in rows and drive groups of valves arranged in columns.
 2. The tool of claim 1, wherein the valve controller provides an air pressure signal to the valves to control the valves between open and closed states.
 3. The tool of claim 2, wherein the valve controller provides a fluid flow to valves.
 4. The tool of claim 1, wherein the valve controller provides an air pressure signal to valves in a corresponding row.
 5. The tool of claim 1, wherein the valve controller provides a fluid flow to valves in a corresponding column.
 6. The tool of claim 1, wherein the capillaries are arranged to move relative to the body.
 7. The tool of claim 1, wherein controlling flow for a capillary includes allowing fluid to enter into the capillary and/or expelling fluid from the capillary.
 8. The tool of claim 1, wherein the valve controller is mounted to the body.
 9. The tool of claim 1, wherein the valve controller is adapted to control the valves to simultaneously control flow for a plurality of capillaries, wherein control of flow for the capillaries includes allowing fluid to enter into the capillaries and/or expelling fluid from the capillaries.
 10. The tool of claim 1, wherein: the valve controller comprises a plurality of switches that provide signals to the valves, the number of switches being at most M+N.
 11. A sample handling tool, comprising: a body; a first number of capillaries mounted to the tool body, each of the capillaries constructed and arranged to remove material from a work area and deposit material on a work area; and a controller that is adapted to control the capillaries so as to simultaneously actuate a plurality of the capillaries, and is adapted to control the capillaries so as to individually actuate each capillary independent of other capillaries; wherein the controller includes M switches associated with M columns of capillaries, each of the M switches corresponding to and providing signals to a corresponding column, and N switches associated with N rows of capillaries, each of the N switches corresponding to and providing signals to a corresponding row.
 12. The tool of claim 11, wherein the controller includes a plurality of actuators that each correspond to a capillary and control fluid flow for the corresponding capillary.
 13. The tool of claim 12, wherein each of the plurality of actuators receives an air pressure signal to actuate a corresponding capillary.
 14. The tool of claim 12, wherein each of the actuators is arranged to control a fluid flow in the corresponding capillary.
 15. The tool of claim 12, wherein each actuator includes a valve that is adjustable between open and closed states to allow fluid to flow in a corresponding capillary.
 16. The tool of claim 11, wherein the plurality of capillaries are arranged in an M×N array.
 17. The tool of claim 11, wherein the controller actuates capillaries to allow fluid to flow into selected capillaries by capillary action.
 18. The tool of claim 11, wherein the wherein the controller actuates capillaries to expel fluid from selected capillaries.
 19. The tool of claim 11, wherein the controller controls selected capillaries to expel a controlled volume of fluid.
 20. The tool of claim 11, wherein actuation of a capillary includes one of aspirating fluid into and expelling fluid from the capillary.
 21. The tool of claim 11, wherein the controller is mounted to the body.
 22. The tool of claim 11, wherein the controller can actuate selected groups of capillaries to simultaneously pick up or expel fluid.
 23. The tool of claim 11, wherein the tool includes a first number of capillaries, and the controller is adapted to individually actuate each of the capillaries using a second number of signals that is less than the first number. 